Alright, I keep trying to sell you on this Cast Iron (and Carbon Steel) idea despite what you’ve heard, so lets get into it.
We’re going to start by explaining why you need to care for your cast iron and what you need to do, then we’re going to get into common myths, what the reality is and why.
WHY DO I NEED TO CARE:
Cast iron is like any good tool. Ask your mechanic, their favorite tools require a bit of oil, cleaning, maybe some tuning so on. These are not marks of a BAD tool, these are the marks of a tool that has a job to do and likely does it so well it’s worth the maintenance to make sure it continues to run at peak performance. Cast iron and Carbon Steel are just like that. I’m going to talk in terms of Cast Iron as it’s the harder one to care for and typically if you’re springing for the investment that is Carbon Steel, you’ve cut your teeth on Iron and know what you’re getting into.
The reason you need to care is that cast iron is not alloyed the same way as Stainless Steel and it can rust. That’s the biggest reason. The happy “accident” is that the way you maintain cast iron from rust can make your pan non-stick if you do it right. How you do this is by “Burning” layers of oil to your iron to create thin layers that coat and protect the iron within.
WHAT DO YOU NEED TO DO:
Three things: Clean it gently, dry it completely and season it.
Drying it completely is easy. When you wash your pan, dry it on the stove. That’s it. Just toss it on the stove, let your pan get hot and evaporate the water on your pan. Just that easy. You can also dry it with either a bone dry towel or paper towels, but the upside to drying it on the stove is that it’s easy to put a light seasoning on it while drying already. What does that mean? Well….
How do I season my pan? Burn oil! Well, not really. You don’t actually burn oil to the pan, what you’re doing is polymerizing layers of oil into an almost silicon like layer that “seasons” the pan. You’ve probably heard that term “season your pan”, “Pre-seasoned pans”, “don’t damage the seasoning”. That seasoning is those layers of polymerized oil. That’s it!
So what does it take to get your pan seasoned?
Oil and paper towels. Tongs if you want to make sure you don’t burn your finger tips. That’s it. What kind of oil? There’s a LOT of arguments about this, but honestly, the science says that you want an oil that is flavor neutral, free of impurities and polymerizes at a relatively low heat. How do you find this heat? Well, look up the smoke point of oil. When oil starts smoking, it’s polymerizing, this is why people call it ‘burning’ on your oil. This means that the absolute best is something like Flaxseed Oil, which smokes at ~225 degrees F, but who keeps a bottle of that randomly on hand? To use what you already have in your kitchen, vegetable shortening like Crisco smokes at 360, is cheap and easy to use! Olive oil is your next best bet at 400 degrees.
So how do you do it? You heat your pan and then apply an even, thin layer of oil. The best way to do this in my experience is by applying oil or shortening directly to a paper towel and rubbing it into the pan once it’s hot and then letting it get back up to smoking. Ideally, you’d let it smoke for about half an hour, but even this little bit of smoking helps. To put a full seasoning layer on, put the pan into your oven at 400 degrees for half an hour (cooking surface down), turn off the oven and let it cool in the oven. Boom. Done. You’ve not only completely dried your pan out, but you’ve applied yet another layer of seasoning making your pan more durable than before!
When I first acquire a pan, even a “pre-seasoned” pan, I never trust the seasoning on it. I advise spending a couple of hours applying 4-6 layers on it in the method described above. Every half an hour, pull the pan, re-apply fat, place it back in the oven cooking face down (you do this so that fats will drip out instead of pooling and causing uneven areas in the cooking surface.) repeat until you’re satisfied.
And if you’re wondering if you’re seasoning your pan while cooking, the answer is probably yes! Every time you use oil in your pan and it starts to smoke, you’re putting thin layers of seasoning on your pan. This is why the best pans are older pans that have been well cared for and regularly used! Functionally, you’ll develop a good seasoning that will be pretty non-stick, after pre-seasoning the pans with about four to six layers and around 6 weeks of regular use!
Now about that Gently Clean thing I mentioned earlier. It’s not that hard. If you’ve properly maintained a seasoning, you shouldn’t need to scrub your pan that hard. No stiff bristled brushes, no abrasive cleaners like Comet or Ajax, no steel wool. That’s about it. Most dish soaps these days are VERY gentle (unless you’re 99.9% of bacteria) but don’t include abrasives. Even the ones that are “tough on grease” won’t do much to polymerized fats once they’re really cooked in. If you’re having trouble cleaning something off your pan, throw a finger of water in the bottom, put it on the stove to boil for 2-3 minutes and give it another go. That’ll clear up cooked-on food most of the time!
What if your pan rusts? If you don’t dry it out and water sits in the bottom of your pan for a while, it’s possible you can get a bit of rust in your pan. It will probably be surface rust only. If this happens, scrub out the rust with the scrubby side of a kitchen sponge and then intentionally season your pan another 2-6 layers.
That’s it! That’s all you need to know. That’s all the care and maintenance you should need to worry about.
So lets talk about myths!
MYTH: If my pan rusts, it’s done. Dead. An ex-pan!
Reality: Nope. More often than not the rust you’ll get is surface only. If you clean the rust out and it’s still smooth, just reseason a layer or three as mentioned above. When I say more often than not, I mean that I’ve left pans outside for over a week and when I cleaned it out, nothing but surface rusting. If you DO have pitting, it can be a more major cleanup job. if the pitting is shallow, you might be able to fill it in with some seasoning, but bad pitting might mean that you need to resurface your pan. This is NOT a dead pan by any means, but does require some work to fix.
MYTH: Bacon grease or lard make the best seasoning oils
REALITY: First off, for reasons we talked about above, Bacon Grease is right out. It’s full of salts, nitrates and impurities. Lard is fine. It has a smoking point of 375, which is similar to olive oil but it’s no better and you probably don’t just have a bucket of it laying around already. I’ve used pans that were seasoned with ONLY lard versus pans that have been seasoned with whatever oil you happen to have laying around and noticed no difference at all. Shortening still takes my vote.
MYTH: You can’t wash your cast iron with soap/get it wet:
REALITY: As we’ve already discussed, this just isn’t true. Most detergents these days are incredibly mild. You defiantly don’t want to leave your pan in a sink of soapy water, but you can absolutely give it a wipe out with soap and water, maybe hit it with a brillo pad or a standard dish brush without ruining anything. Just make sure it’s all nice and dry after you’re done and maybe throw a layer of oil at it while you’re at it just to be safe.
MYTH: You can’t use Cast Iron on glasstop stoves
REALITY: So long as you don’t slide your cast iron around or drop it, it’s fine. See my writeup on cooktops for more info.
MYTH: You can’t cook tomato sauce in a cast iron pan
REALITY: You probably shouldn’t for extended periods of time, so best to not simmer your sauce in one. That said, a properly seasoned pan is just fine to use for regular cooking with tomato, lemon or any other acidic or basic food you like.
MYTH: You can’t use metal utensils on cast iron
REALITY: Just wrong. Sure, if you’re scraping hard at your pan with your metal spatula, you might remove some of your seasoning, but the answer here is….season it. If you scrape, clean or scrub through that you see bare metal, the answer become “do a full 4-6 layer reseason in the oven”.
See! Cast iron isn’t nearly as scary as you might have thought. Please let me know if you have any other Cast Iron questions you’d like answered.